Method and apparatus for stopping web movement



Oct. 18, 1966 P, w BU 3,279,370

METHOD AND APPARATUS FOR STOPPING WEB MOVEMENT Filed May 5, 1964 INVENTQR 6 TE? What/RM B vc' CIA-4% AT TOR NEYJ United States Patent 3,279,370 METHOD AND APPARATUS FOR STOPPING WEB MOVEMENT Peter William Bunce, 56, The Vineyard, Richmond, Surrey, England Filed May 5, 1964, Ser. No. 364,935 Claims priority, application Great Britain, May 7, 1963,

6 Claims. (Cl. 101-292) This invention relates to a method and apparatus for stopping a continuously moving web, in particular to enable marking, punching, labelling or fixing of tear strips to be carried out.

The treatment of a continuously moving web of material, for example synthetic resin film such as polyethylene, used for packing purposes presents difficulties since to effect such operations as marking it is necessary for that part of the web being treated to remain stationary during the operation. In one method of treatment at present in use the forward movement of the whole length of web is stopped completely when treatment such as marking is to take place. Intermittent stopping of the whole length of the forward-moving web of material is however undesirable in a continuously operating packing assembly. It also causes strain on the machinery and on the material of the web.

It is an object of the present invention to provide a method for stopping a continuously moving web of mate rial in which only that part of the web to be treated is stationary during the operation. It is a further object to provide apparatus to effect such method.

According to the invention there is provided a method of stopping a continuously moving web of material which in order to effect a marking or like operation comprises rendering stationary that part of the web which is to be treated and simultaneously increasing the length of travel of the web entering the treatment area and decreasing that of the web leaving the treatment area so that the apparent total forward movement of the web remains substantially the same as when no treatment is taking place.

The increase of the distance of travel of the web entering the treatment area and the decrease thereof leaving the treatment .area is preferably brought about by allowing the web to run over input guide means, for example an input roller and output guide means, which may again conveniently be a roller, which guide means are connected to each other and which are normally biased away from the direction of movement of the web. When it is desired to treat the web the forward movement of that part of the web which is to be treated is stopped, for example by suitable friction brake, and simultaneously the bias on the input and output guide means is removed. The forward travel of the web then pulls the output guide means forward which brings with it the input guide means. The length of travel of the web is thus increased as it enters the treatment area and decreased as it leaves the treatment area. The total forward movement of the web is therefore effectively not halted during the marking operation.

When the treatment operation is complete the brake is removed and the input and output guide means return to their biased position.

The invention also provides apparatus for effecting the stopping of a continuously-moving web of material to effect a marking or like operation comprising input guide means for the web to be treated, brake means for braking the web entering the treatment zone and output guide means for receiving the moving web and means to bias the input and output guide means against the direction of travel of the web, connecting means being provided whereby when the web is rendered stationary in the treat- 3,279,370 Patented Oct. 18, 1966 ing zone the bias on the input and output guide means is removed so that the length of travel of the input web is increased and the length of travel of the output web is de creased.

In a preferred embodiment of the invention the input and output guide means comprise rollers which are connected to an arm which is biased by an air pressure cylinders against the direction of travel of the web. When it is desired to treat the web this bias is removed by release of air pressure in the cylinder. Actuation of this release may be brought about by a solenoid operated release means connected to the marking unit.

Alternatively, the air pressure may be double-acting, that is to say the piston may be moved positively by air pressure in either direction. Normally it will 'be arranged so that the bias of the rollers is against the direction of travel of the web. When marking is to take place, however, the bias may be positively removed by introducing air under pressure .at the opposite end of the cylinder to equalize the normal biasing air pressure.

The coordination of the operation of the marking head or like mechanism, the actuation of the brake means and the removal of the bias may be effected in any convenient manner. Suitable mechanisms for effecting this include an air operated valve system in which air is introduced simultaneously under pressure to the brake means, the marking head and the biasing mechanism.

The method of stopping the web according to the invention provides considerable advantages over the hitherto known stopping methods. Thus, the mechanical strain on the web being marked is considerably reduced, Which makes tearing of the web less likely. Also the treated web can enter any other continuously operating process, for example a subsequent wrapping process, in a continuous manner, since the total movement of the web is not affected by the treatment procedure. This is a simplification over the case where it is necessary to arrange for the total movement of the web to be intermittently stopped so that it is prevented from entering a subsequent process in a continuous manner.

It should be emphasized that although the stopping of the web is particularly useful where the web is to be marked, it is also of considerable use where the web is to be punched or labelled or it is to have tear strips afiixed thereto.

A preferred embodiment of the invention will now be described with reference to the accompanying drawings in which:

FIG. 1 is a perspective view of apparatus according to the invention.

FIG. 2 is a diagrammatic representation of web passing through the apparatus shown in FIG. 1.

Referring to the drawing, apparatus according to the invention comprises a pair of upright columns 1 and 1, which act as support members which have secured to them lower transverse support members 2 and 2 and upper transverse support members 3 and 3. Positioned between the lower transverse support members 2 and 2 there are provided two idle rollers, that is a lower idle roller 4 and an upper idle roller 5. Positioned between the upper transverse support members 3 and 3 there is provided a spring loaded pinch roller 6 and a roller 7 which is provided with a disc brake 8; this disc brake is air-operated by means of a spring return plunger. There is also provided a further idle roller 9 at the output side of the apparatus. At the top of the columns 1 and 1 there is provided a pair of transverse beams 10 and 10 which act as a support for a marking unit 21 (shown diagrammatically). Support members 22 are provided to support a platen 23.

Positioned on the lower support member 2 is a double acting air cylinder 11 with a piston 12 which actuates a crank 13 to impart rotary movement to a shaft 14. Depending from this shaft 14 is an arm 15 having a corresponding arm (not shown) facing it. Between these two arms there is provided a shaft 16 at both ends of which are provided freely rotatable cross members 17. Positioned between these cross-members are idle rollers 18 and 19.

In addition to the rollers shown in FIG. 1 further rollers present in the apparatus are shown in FIG. 2 which cannot be conveniently shown in FIG. 1. These rollers comprise an upper and lower idle roller 20 and 21 respectively which correspond to rollers 4 and 5 and which are positioned between the same support members. The direction of travel of the web through the machine is indicated by the broken line in FIGURE 2.

The apparatus is operated by air pressure which coordinates the operation of the disc brake, the marking unit and the biasing cylinder.

In its inoperative position, air supplied from a main supply under pressure enters inlet 24 of the cylinder 11, thus biasing the rollers 18 and 19. The entry of air to the other parts of the apparatus is controlled by a solenoid operated valve system (not shown) which supplies and exhausts air from ports 25 and 26 on the marking unit, 27 on the disc brake and 28 on the biasing cylinder. In the inoperative position port '26 is supplied with air to keep the marking head of the marking unit off the web. Ports 25, 27 and 28 are at the exhaust position, so that the disc brake is not operative and the rollers 18 and 19 are in the biased position.

When it is desired to mark the web air is introduced into ports 27, 28 and 25 and exhaust from port 26. Under these conditions the air pressure brings the disc brake into operation, to stop the movement of the web, substantially equalizes the air pressure in the biasing cylinder 11 so that the rollers are drawn to the right (see FIG. 2) and also activates the marking head which eitects marking of the web.

When it is desired to return to the inoperative position ports 25, 27 and 28 are exhausted and air introduced into port 26. The head of the marking unit is thus raised clear of the web, the disc brake rendered inoperative and the bias returned to rollers 18 and 19.

I claim:

1. A method of intermittently stopping a section of a continuously advancing web in a treating zone comprising continuously feeding and withdrawing said web toward and from a predetermined path about first and second guide members respectively trailing and leading said web section along said predetermined path, said guide members being coupled for simultaneous movement in a first direction for increasing and decreasing the path of said web respectively trailing and leading said intermittently stopped section and in a second direction for decreasing and increasing the path of said web respectively trailing and leading said intermittently stopped web section, and alternately biasing said guide members in said second direction and releasing said guide members for movement in said first direction substantially solely under the influence of said advancing web whereby said section of said web along said path between said guide members is intermittently stopped and said guide members are moved in said first direction by the pull of said web forward of said stopped web section, and said section of said web between said guide members is advanced and said guide members moved in said second direction under the influence of said bias.

2. The method of claim 1 including the step of engaging and positively stopping said web section during the release of said guide member bias.

3. The method of claim 1 including the step of marking said web section during the stopping thereof.

4. A web handling apparatus comprising a first relative ly stationary guide means defining a work station whereat it is desired to stop the web, a pair of longitudinally spaced second and third web guides spaced from said first guide means and interconnected for simultaneous movement, means for directing a web toward a path about said second web guide along said first guide means and from said first guide means about said third web guide, and means for alternately biasing said second and third web guides for movement in a rearward direction and for releasing said second and third web guides for substantially free movement in a forward direction under the pull of said advancing web.

5. The apparatus of claim 4 including means for braking said web along its path between said second and third web guides simultaneously with the release of said biasing means.

6. Apparatus for eifecting marking of a continuously moving web of material comprising a first roller for receipt of said web, a second roller for adjusting the length of travel of the web, a third and fourth roller for guiding the web to the marking zone and brake means associated with the fourth roller to effect braking of the web, a fifth and sixth roller for take olf of the web, a seventh roller for actuating said marking head when the web in the marking ing zone and a final eighth roller for guiding the web leaving the apparatus, a marking head for marking an area of web between the fourth and fifth roller and means for actuating said marking head when the web in the marking zone is stopped by the brake means, which actuation means are coordinated with a double-acting air cylinder which is effective to remove the bias normally present on the second and seventh rollers against the direction of travel of the web, when the brake means are operative, to increase the length of travel of the web entering the marking zone and decrease the length of travel of the web leaving it.

References Cited by the Examiner UNITED STATES PATENTS 2,862,233 12/ 1958 Brown 226--24 X 2,898,995 8/1959 Funnell 83-262 X 3,053,129 9/1962 Aronson 22612O X 3,084,841 4/1963 Hata 226l24 X 3,098,405 7/1963 Lyon 83-236 3,137,427 6/1964 Martin 226168 X M. HENSON WOOD, JR., Primary Examiner.

ROBERT B. REEVES, Examiner.

R. A. SCHACHER, Assistant Examiner. 

4. A WEB HANDLING APPARATUS COMPRISING A FIRST RELATIVELY STATIONARY GUIDE MEANS DEFINING A WORK STATION WHEREAT IT IS DESIRED TO STOP THE WEB, A PAIR OF LONGITUDINALLY SPACED SECOND AND THIRD WEB GUIDES SPACED FROM SAID FIRST GUIDE MEANS AND INTERCONNECTED FOR SIMULTANEOUS MOVEMENT, MEANS FOR DIRECTING A WEB TOWARD A PATH ABOUT SAID SECOND WEB GUIDE ALONG SAID FIRST GUIDE MEANS AND FROM SAID FIRST GUIDE MEANS ABOUT SAID THIRD WEB GUIDE, 